This invention relates to a room air conditioner which can provide a comfortable environment in accordance with the desire of the user, and particularly to an air conditioner which can quickly adjust the room temperature when the user feels hot or cold during the operation of the air conditioner so as to rapidly alleviate his sense of discomfort.
FIG. 1 illustrates in the form of a block diagram the control system of a conventional heat pump-type room air conditioner which is disclosed in Japanese Patent Laid-Open No. 56-137029. In the figure, numeral 1 is an operating switch which turns on a microcomputer 5. Numeral 2 denotes a semiconductor temperature-sensitive resistive element such as a thermistor for detecting temperature of a room being air conditioned and producing an analog output signal corresponding to the temperature. The output signal from the temperature-sensitive element 2 is converted into a digital signal by an A/D converter 3 and input to the microcomputer 5. A temperature setter 4 inuts a signal to the microcomputer 5 corresponding to a room temperature set by the user of the air conditioner. The microcomputer 5 is in the form of an LSI chip running on a prescribed program. It comprises a room temperature memory 7 which periodically reads the output from the A/D converter 3 and stores it as room temperature data Tr, a set temperature memory 8 which stores as set temperature data Ts a value which varies within a prescribed range from a predetermined central value based on an increase or decrease signal from the temperature setter 4, and a comparator 9 which compares the room temperature data Tr from the room temperature memory 7 and the set temperature data Ts from the set temperature memory 8 and sends a run or stop signal to a compressor 6.
The operation of the illustrated air conditioner during heating mode will now be explained. When the operating switch 1 is closed, the microcomputer 5 begins to operate in accordance with the above-mentioned program. The comparator 9 compares the room temperature data Tr with the set temperature data Ts. When Tr&lt;Ts, the comparator 9 sends a run signal to the compressor 6, the air conditioner beings heating operation, and the room temperature rises towards the set temperature Ts. When the room temperature data Tr exceeds the set temperature data Ts, the comparator 9 sends a stop command to the compressor 6, and the air conditioner stops heating operation. Later, when the room temperature decreases and Tr&lt;Ts, a run command is again sent to the compressor 6. This process is continuously repeated, the air conditioner performs intermittent heating operation, and the room temperature is maintained at substantially the set temperature Ts.
With the conventional room air conditioner of this type, the user controls the room temperature by adjusting the set temperature Ts in the temperature setter 4. However, the user can not directly input the sense of physical hot or cold environment into the temperature setter 4, but must mentally convert his desire for a warmer or cooler environment into a new set temperature and input it to the temperature setter 4. The operation of the air conditioner becomes complicated for it requires the user to have a good sense of the temperature scale. It is therefore difficult for a child, who does not have an understanding of temperature, to operate the air conditioner. Furthermore, if the temperature setter 4 requires the temperature to be input in accordance with the Fahrenheit temperature scale, it is difficult to properly set the temperature for a user who is accustomed to the Centrigrade scale.
As can be recognized in the conventional air conditioner, if the user changes the set temperature when the air conditioner is operated in a temperature transition mode and the room temperature has yet to reach the previously set temperature, the the operation of the air conditioner will be based on the newly set temperature. However, if the user alters the set temperature when he is unaware that the room temperature is still changing from an initially warmed or cooled level, the new temperature is likely to be too high for heating or too low for cooling. Therefore, he can easily end up setting the temperature at a level which he will find uncomfortable.
Furthermore, in the conventional air conditioner, when the user feels uncomfortable and changes the set temperature, the room temperature only gradually approaches the new set temperature, and it takes considerable time to relieve the user's feeling of discomfort.